Well, it seems that you have to text in the dark environment, because this is not very good. As you know, in the dark the cell phone is the only source of light, and your eyes are so close to the screen, which gives out a lot of harmful lights to your eyes. And you can simply do nothing about it. If you text in the bed, the damage could be even worse. So, I suggest you don't do this for too long.
Yes, it is true that texting in the dark is bad for the eyes. The screen from the phone will stimulate your eye nerves. If you do this often, you will have weak eye nerves. And your eyes will be short sighted. In a word, too close distance between the eyes and the cell phones will be bad for the eyes, especially in the dark. You keep notice of this.
Generally speaking, texting in the dark will do some harm to your eyes. As we all know that while texting the dark, we have to strain our eyes to focus on something, like the screen of the computer. If you text in the dark for a long time, the nerve around your eyes will keep strained, and then your eyes are easily to get infected and then I think the victim will be you and your eyes. As a matter of the fact, there are more possibilities for your eyes to get infection and bloodshot and irritated. However, if you have already been wearing glasses for some time, you can text in the dark, but pls keep in mind that you cannot do it for long time. Because the prescription glasses can adjust the distance between you and your computer so that you do not need to make your nerves strained for long time, you can solve some emergency when you have to text in the bark. No matter whether you text in the dark or not, you should make your eyes have a rest after working. Hope this help you.